George louis bene jeak messier



Dec. 20, 1932. R, ME S, Re. 18,696

PNEUMATIC SUSPENSION FOR AIHPLANES Original Filed Sept. 7.: 192a Fig.1

E O 22 as -15 ll 1 l2 ll 4W.

I II 'I IH wl lrl l GEORGE Lows RENE JEAN MESSIER INVENTOR ATTORNEYS 40 of apping sags,

Ream: Dec. 20,1932

' UNITED STA TES.

PATENT OFFICE GEORGE LOUIS m JEAN HEBSIEB, OI IONTROUGE, FRANCE PNEUI A'IIC SU SP EHSION 10B AIRPLANE Original Io. 1,780,581, dated Iovember 4, 1930, Serial No. 804,433, filed September 7, 1928, and in l'ranco September 28, 1927. Application for reissue filed November 8, 1982. Serial No. 0,98;

port only a predetermined maximum static overload, it' will be immediately understood 10 that, for absorbing the greatest possible vi's viva,'it is necessa that the opposed resilient resistance should approximately constant and in the neighbourhood of the maximum admissible static overload.

If use is made of a, suspension by'means of rubber, metal s ring or com ressed air, the overload curve .1n function the collapsings is. either an inclined straigIht line, or a curve of a hyperbolic nature. 11 both cases'.the 20 optima conditions above defined are far from being: obtained. I

The present invention has for object an improved suspension system for airplanes, allowin the said optima conditions to be 25 approac ed.

. It is based on the combination of a resilient braking by com ression of air, and of a bydraulic braking y delivery .of liquid through orifices of reduced cross section, this cross 80 section bein either constant, or variable according to t e position of the piston and the direction in wlnch it moves,'in such a manner (see Fig. 1)

1. As to superpose on'a curve of pneumatic 86 braking of rising hyperbolic nature (1-) a curve of hydraulic braking (2), of descending nature, so that the resultin curve (3) 1 approaches ahorizontal straightline. In Fi 1, the abscissa: correspond to the beating the ordinates represent the forces oppose o the bending. The curve (2) is variable according tothe speed of the airplane at the time 'of contact with the ground. 2. As to permit of braking the rebounding 'of the airplane, that is to say, the relaxation of the resilient systems, in an independent manner. I

In the following description, it will be assumed that the gas employed is a compressed gas. But it must be understood that any gas or fluid may be used, carbonic acid for instance, undera free form or enclosed in a solid, spongy rubber for instance.

In the case of an airplane provided with 'two wheels and a tail skid, the" suspension comprises:

(a) two suspensionapparatus arranged adjacent to each wheel, at the front;

(b) a rear apparatus-interposed between the tail skid and the fuselage.

Figure 2 diagrammatically illustrates an example of such a device applied to a wheel;

' with a slight inclination to the vertical, comprises a cylinder 4 in which a piston 5 can move; onthe latter is arranged a body of liquid 6 on the top of which is a compressed air cushion 7. The rod .5 of the piston-is pivoted at a on the landing chassis carrying the wheel b of the air lane, the helf-axle o is pivoted at d under t 1e fuselage e.

A diaphragm 8 secured to'the c linder separates in two parts the body of iquid; it is perforated with two orifices 9, 10; the cross. section of these orifices can be regulated from the exterior by means of controlling screws 11, 12, for instance; two flap-valves 13, 14, arranged in reverse direction, compel the liquid to pass through one of the orifices, 9, when the piston moves upwards, and through the other orifice 10, when the piston moves downwards. The apparatus comprises also a tube for securing the cylinder, and filling up orifices 16, and 17 for the liquid and the compressed fluid. f

It will then be-under'stood that, uponlanding, the vertical speed of the airplane bein a maximum upon contact with theground and subsequently decreasing progressively,

the stress of hydraulic braking, approximately proportional to the square of-the' orifice 9, also decreases from a maximum.

speed of flow of the liquid through the mo crease the value of the hydraulic braking during the last period of the upstroke of the piston.

For that purpose (Fig. 4), the diaphragm 8 is perforated with a third orifice 18,

through which a rod 19 of variable cross section, integral with the piston 5, passes. In order that this orifice may serve in one direction only, that of the arrow f, it is surmounted by a ,tube 20 closed at its upper part and perforated with a side orifice 21, provided with a flap-valve 22 so arranged as toprevent-the passage of the liquid in the reverse direction.

The apparatus can be adjusted in two different manners: Y

1.Under the normal load, the piston is at a certain distance from the lower ,bottom 4' of the cylinder, sothat the heating or flapping of the wheels may also take place downwardly;

2.Under the normal load the pressure of the compressed fluid is regulated to such a value that the piston rests on the lower bottom. I

In the latter case, as well as in the first one, when the airplane is in flight, the fluidtightness of the piston can be; completed by a packing, made of metal, fibre or any other material, on which the piston rests.

What I claim is ,1. In a pneumaticsuspension for the landing gear of airplanes, in combination, a cylm er pivotally attached to said airplane, a piston pivoted on the landing gear and contained insaid cylinder, a volume of gas in said cylinder, a volume of liquid in said cylinder, a diaphragm centrally positioned in said cylinder below the level of said liquid, said dia hragm being provided with a central ori cc and intermediate orifices, a rod havin a restricted portion, inte al with said 'plston and passing throu h said central orifice, a closed tube mounte on said dias phra over said central orifice being'pro- 'vid with-'a side orifice and a fi valve covering said side orifice when sai piston descends.

2. In a pneumatic suspension for the landin gear of airplanes, in combination, :1. cylfor adjustably var' ing the area of said intermediate orifices, ap valves hingedly positioned above and below said intermediate orifices, a rod having a restricted portion, integral with said piston and passing through said central orifice, a closed tube mounted on said diaphragm over said central" orifice being provided with side orifice and a flap valve covering said side orifice when said piston descends.

3. In a pneumatic suspension for the landing gear of alrplanes, 1n combination, a cylinder pivotally attached to said airplane, a-

piston pivoted on the landing gear and contained in said cylinder, a volume of gas in said cylinder, a volume of liquid in said cylinder, a diaphragm centrally positioned in .said cylinder below the level of said liquid,

said dia hragm being provided with a central ori cc and intermediate orifices, a rod having a restricted portion, integral with said piston and passing through said central orifice, a closed tube mounted on said diaphragm over said central orifice being provided with'a side orifice and a valve covering said side orifice when said piston descends.

. 4. In a pneumatic suspension for the landing gear of airplanes in combination, a cylin er pivotally attached to said airplane, a piston pivoted on the landing gear and contained in said cylinder, a volume of gas inv fice, a closed tube mounted on said diaphragm oversaid central orifice being provided with a side orifice and a valve covering said side I orifice when said piston descends.

GEORGE LOUIS RENE JEAN MESSIER.

in er pivotally attached to-said airplane, a

piston pivoted on. the landing gear and contained in said cylinder, a volume of gas in said cylinder, :1. volume of liquid in said cylinder, a diaphragm centrally. positioned in said cylinder below the level of said liquid,

said dia hragm being provided with a central ori cc and intermediate orifices, means 

